About 21,000 fish at an aquatic research center at the University of California, Davis died from exposure to chlorine in what the university described as a “catastrophic failure” that had shocked researchers and would significantly delay their studies.
The university said in a statement that it would investigate “where our process fell short” and launch an independent external review.
“We share the grief of the faculty, staff and students who worked to care for, study and conserve these animals,” UC Davis said.
The fish were found dead Tuesday in several tanks at the Center for Aquatic Biology and Aquaculture, which spans five acres and is home to research programs focused on maintaining California’s aquatic species and supporting sustainable aquaculture production, according to the center’s website.
Laurie Brignolo, executive director of the animal care research and education program at UC Davis, said Sunday that university officials believe the source of the chlorine was a chlorination system used to decontaminate water. with fish pathogens.
If that was the source, university officials didn’t know how the chlorine got into the aquariums. One possible explanation is that there was a backup in the water pipe system that caused the chlorine to move in the wrong direction, Ms Brignolo said.
UC Davis said it was committed to “understanding what happened and making changes to the facility” to prevent such a failure from happening again.
The university said while many of its other aquatic research facilities “don’t have the same potential for chlorine exposure, some do,” and it would assess the risk.
The centre, which was built in the 1950s, had never seen such an “overall loss” of fish, Ms Brignolo said. Workers carry out “daily quality assurance of the pump and the water passing through it”, she added. The day before the loss, she said, the roughly 21,000 fish had been checked.
Overnight, however, enough chlorine had entered the tanks that there was an amount similar to that of tap water – a dangerously high amount for fish, Ms Brignolo said. Fish are not supposed to be kept in water containing even small amounts of the chemical.
The chlorine has damaged the sensitive gills and skin of the center’s various fish species, including green and white sturgeon and endangered Chinook salmon.
Within 12 hours, almost all the fish were dead.
Ms Brignolo said she received an email on Tuesday morning from the centre’s director, who was one of the first people there that day. The official saw that thousands of fish had died, Ms Brignolo said, and called it a “tragic loss”.
Center workers went tank by tank and counted the losses. Only a hundred fish had survived.
“It’s absolutely devastating,” she said.
Some researchers and graduate students used fish to study the effects of disease and environmental change on certain species.
The huge loss of fish at the center won’t completely end the researchers’ studies, but it will set them back significantly, some for years, Brignolo said.
The loss also had an emotional impact on those who work there. The university has implemented a bereavement program for students and staff who have been affected.
“Their role is to provide a safe environment for several fish that are used for research purposes,” Ms Brignolo said. “And it’s an absolute sense of failure.”